Connectivity Issues with Citrix

I have a Citrix Server which stopped accepting remote connections “suddenly”. It’s on a ISA Server, but has been working correctly and securely since it was installed. I was wondering if anyone using Citrix also has had any problems since the latest virus/worm issues?

My internal users can get Internet and e-mail fine, however no incoming connections are accepted. I’ve looked through Citrix’s KB and none of their suggestions helped. I have not installed SP4 since I’ve read about others having problems with it and haven’t seen any “resolves” for the various issues caused by SP4.

Any suggestions? My remote offices are “down” until I can get this issue resoved.

Thanks.